The field of the invention generally relates to clothes dryers, and more particularly relates to apparatus and method for circulating air through a clothes dryer and for collecting and incinerating lint in the air.
U.S. Pat. Nos. 4,665,628 and 4,669,199 disclosed a clothes dryer that had an axially-mounted fan that blew a high volume of air into the clothes drum from the rear. The entire length of the drum had perforations through which the large volume of air radially exited the drum. A substantially air-tight casing spacedly surrounded the drum thereby defining a circumferential recirculation passageway for the forced air to flow longitudinally to the rear. An annular lint screen was mounted to the drum and extended rearwardly therefrom. The flow path of the lint laden air was radially inwardly through the lint screen so that the airborne lint was deposited on the lint screen. A burner was positioned at one rotational location adjacent to the lint screen, and the lint screen rotated past the burner such that lint deposited around the entire circumference of the lint screen rotated through or close to the flames from the burner thereby incinerating the lint. According to a design objective of that dryer, a high percentage such as, for example, 90 percent of the air passing through the screen was then recirculated back into the drum by the fan. A second fan communicating with the air within the cylinder of the lint screen was used to exhaust a small percentage such as, for example, 10 percent, of the air.
The above-described clothes dryer had some drawbacks. First, the second fan was necessary in order to draw exhaust air positively from the high volume of air that was being forced into the drum and recirculated back around. Also, because the air was exhausted from the low pressure side of the fan inside the cylinder of the lint screen, close tolerance sealing was required to ensure that substantially all of the recirculating air passed through the lint screen thereby depositing airborne lint on the screen. In other words, if lint laden air were permitted to leak around the lint screen, the exhaust air would not have been lint free. Further, because of the location of the burner within the turbulent air flow of the high volume recirculation air, a power burner was used to provide optimum flame characteristics.